One of the new features in WebCenter PS3 is the new navigation model. It allows you build dynamic models . You can add all kinds of resources in the navigation model like external links, pages from your portal, taskflows, portals, content from a content server and so on.
When your portal is content driven, you definitly want the ability to add links to different items based upon some criteria instead of adding all the content manually. This can be achieved by adding a content query to your navigation model. A content query is based upon the CMIS standard. CMIS stands for Content Management Interoperability Services which is a standard for improving the interoperability between different content management servers. For example Alfresco, IBM, Microsoft, SAP,... support this standard.